986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Noticed Some Wobble on Crankshaft Serpentine Belt Pulley

jakeru · 07-16-2017, 09:09 PM

Hey folks,

In trying to diagnose some metallic rattling sounds of my 2001 Boxster base/2.7, I noticed my crankshaft serpentine belt pulley has some noticeable axial runout to it! The following video is on cold-start-up:
trim.262D9F95-2809-46F9-ADB5-1734EEA01D45.MOV - Video - VideoSprout

This next video is after it has been warmed up:
trim.A3E7C7EE-9CCB-4EEB-A065-AC4A1F58314E.MOV - Video - VideoSprout

There seems to be a metallic noise coming from behind the crankshaft pulley, but it's much easier to hear when driving the car, so I'm not sure this is the origin of this noise or not. I'm thinking because pulley bolt seems to be not wobbling, perhaps this is a bent pulley, or a somewhat loose pulley mounting bolt? (If it were loose, it would explain the metallic rattling sound.)

I found a YouTube video that shows someone else with a remarkably similar symptom, shown at 0:09. It seems when replacing the pulley, he found the key way was damaged. Seems like evidence it seems to me of an inadequately tightened pulley bolt!

Have anyone else experienced this? Cheers!

07-16-2017, 09:09 PM	#1
jakeru Registered User Join Date: May 2015 Location: Greater Seattle, WA Posts: 534	Noticed Some Wobble on Crankshaft Serpentine Belt Pulley Hey folks, In trying to diagnose some metallic rattling sounds of my 2001 Boxster base/2.7, I noticed my crankshaft serpentine belt pulley has some noticeable axial runout to it! The following video is on cold-start-up: trim.262D9F95-2809-46F9-ADB5-1734EEA01D45.MOV - Video - VideoSprout This next video is after it has been warmed up: trim.A3E7C7EE-9CCB-4EEB-A065-AC4A1F58314E.MOV - Video - VideoSprout There seems to be a metallic noise coming from behind the crankshaft pulley, but it's much easier to hear when driving the car, so I'm not sure this is the origin of this noise or not. I'm thinking because pulley bolt seems to be not wobbling, perhaps this is a bent pulley, or a somewhat loose pulley mounting bolt? (If it were loose, it would explain the metallic rattling sound.) I found a YouTube video that shows someone else with a remarkably similar symptom, shown at 0:09. It seems when replacing the pulley, he found the key way was damaged. Seems like evidence it seems to me of an inadequately tightened pulley bolt! Have anyone else experienced this? Cheers! __________________ 2001 Boxster Last edited by jakeru; 07-17-2017 at 08:19 AM.